1. Field
The present disclosure relates to a surveying tool and a method of inspecting a nuclear reactor using the same.
2. Description of Related Art
FIG. 1 is partial, cut-away view of a reactor pressure vessel of a conventional boiling water nuclear reactor (BWR). Referring to FIG. 1, a jet pump assembly is disposed in an annular space between the reactor pressure vessel 100 and the core shroud 102. The jet pump riser pipe 104 of the jet pump assembly is secured to the inner wall of the reactor pressure vessel 100 with a jet pump riser brace 106. In particular, the jet pump riser brace 106 includes a yoke section and side members that extend from the yoke section so as to resemble a three-sided square or rectangle. The yoke section of the jet pump riser brace 106 is between the jet pump riser pipe 104 and the core shroud 102. The yoke section of the jet pump riser brace 106 is welded to the jet pump riser pipe 104. The jet pump riser pipe 104 is between the side members of the jet pump riser brace 106. The proximal ends of the side members are connected to the yoke section, while the distal ends of the side members are welded to the inner wall of the reactor pressure vessel 100.
The weld between the yoke section of the jet pump riser brace 106 and the jet pump riser pipe 104 may develop cracks over time. While efforts are made to monitor the integrity of the weld, access to the weld is relatively difficult and limited. For instance, visual inspection techniques have been used to examine the weld, but such techniques are relatively limited both in their accuracy and accessibility. These limitations have made it relatively difficult for reactor operators to fully examine and analyze the integrity of the weld. As a result, issues have arisen with regulators and reactor operations have been constrained.